The present disclosure relates to high intensity discharge (HID) lamps and lighting systems and particularly relates to such systems employing ceramic metal halide lamps wherein an instant start hot re-strike of the lamp is desired. Examples of such devices, particularly a lamp socket for such lamps with an integrated igniter for use with a separate transformer and circuit components, for providing instant start hot re-strike of the lamp at relatively low ignition voltages is described in co-pending application Ser. No. 12/166,548, filed Jul. 2, 2008, entitled “IGNITER INTEGRATED LAMP SOCKET FOR HOT RE-STRIKE OF HIGH. INTENSITY DISCHARGE LAMP” assigned to the assignee of the present application and U.S. application Ser. No. 12/166,532, filed Jul. 2, 2008, now U.S. Patent Publication 2010/0001656, dated Jan. 7, 2010, entitled “A LOW IGNITION VOLTAGE INSTANT START LIGHTING SYSTEM” and assigned to the assignee of the present application.
In the aforesaid HID lamp systems, the lamp and igniter circuitry, including the transformer, have been incorporated in the lamp socket base as an integrated unit which provides hot re-strike and instant ON capabilities for the lamp prior to cooling by providing a relatively high frequency, relatively low voltage, ignition pulse to the lamp and particularly pulses of less than 25 kilovolts. The aforesaid lamp and socket base arrangement has been found particularly suitable for automotive applications. In such applications, the ballast circuitry remains separate and thus requires high voltage cables for interconnection to the lamp base. Although this arrangement may be satisfactory for dedicated system installations such as those provided in automotive applications, it has not been found suitable for replacement of existing lamps in stationary applications and particularly for incandescent, compact fluorescent (CFL), or halogen lamps having a standard screw in base.
HID lighting systems are attractive because they provide intense illumination with substantially less power input than corresponding incandescent, compact fluorescent (CFL), or halogen lamps and thus it has been desired to provide a way or means of replacing existing incandescent, compact fluorescent (CFL), or halogen lamp bulbs with HID lamps. However, the complexity of the circuit componentry required for HID lamps in addition to the problems encountered with hot re-strike of the discharge lamps, have prevented them from achieving wide-spread usage as replacements for incandescent, compact fluorescent (CFL), or halogen lamps.